I wonder if your partition has been "maximized". Consider this fragment
from the cfdisk man page:
m Maximize disk usage of the current partition. This command will
recover the the unused space between the partition table and the
beginning of the partition, but at the cost of making the parti-
tion incompatible with DOS, OS/2 and possibly other operating
systems. This option will toggle between maximal disk usage and
DOS, OS/2, etc. compatible disk usage. The default when creat-
ing a partition is to create DOS, OS/2, etc. compatible parti-
tions.
Run "man cfdisk" and search for "maximize" for more information. In one
place it says that fdisk and some other partitioning tools will maximize
partitions by default. I have run into this problem before-- I
maximized a partition and Windows wouldn't see it, IIRC.
Try running cfdisk and see if you have maximization turned on for that
partition, and can turn it off. I dunno, but it's worth a shot.
Good luck,
Andrew.

Andrew

Thanks for the suggestion, but I fear this is not the problem. I have
deleted the partition in WindowsXP and recreated it several times. Yet on
reboot, even into Windows, it disappears. The only thing that's not
standard in this process is LILO.

FWIW I have just removed LILO from the MBR (fixmbr from winxp CD) and
recreated the partition, rebooted into windows and its still there.
Hooray!!

Gunna try and using NTLDR to boot linux and see how I get on.
Wackojacko